To add to the discussion I'd like to reference a quote from Dewey on the TechNet about AR coatings back in March 2004; "Why wear a latex suit, when a dust bag will do just fine"... That about says it all, don't ya' think? B^D) -Steve Gregory- -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Whittaker, Dewey (EHCOE) Sent: Friday, February 16, 2007 8:19 AM To: [log in to unmask] Subject: Re: [TN] Using Type AR Conformal Coating It is relatively easy to adequately conformal coat assemblies with type AR for Military applications. I've even heard Doug can do it. Having said that I want you to know that I consider type AR a glorified dust bag, but if that's all you need and not a Gucci as Phil wants with his Bunny suit, then fine. I have always believed that one should not rely on any additional electrical benefits derived from the application of a conformal coat to achieve the functional intent of the design. It should only be used to negate the need to derate operational parameters when used in harsh environments. Assessing your needs and understanding your liabilities will make the material choice a lot easier. Process techniques and application guidelines are available for all the materials. Dewey -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of - Bogert Sent: Thursday, February 15, 2007 5:24 PM To: [log in to unmask] Subject: [TN] Using Type AR Conformal Coating February 15, 2007 Folks, we have some military OEM'S that are switching from Type UR conformal coating to Type AR. The main reason for the switch is because it is hard to remove Type UR coating in event of a rework, and certain chemicals sold by the coating manufacturers for UR coating removal are highly conductive and have caused problems since the cleaning process did not adequately remove them. The other reason is we wanted a coating that could be easily removed in event product failed in the field so we could do ATE to quickly find the source of the problem. Our product is used in a military application but it is contained in a cabinet that is dust tight. We have some assemblies that are not coated at all with no known problems. Do any of you folks use Type AR for military product, and if so, what are your experiences using the coating? I have heard about problems using alcohol for coating removal since it goes where you do not want it to go. I have also heard that if a spray process is used, it takes 4 or more passes on each side of the board to achieve the minimum J-STD-001 thickness. At least one source indicated using AR may cause some solder joint reliability issues. Any info you have would be a help. Thanks. --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 1.8e To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF Technet To temporarily halt or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/archives Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 ----------------------------------------------------- --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 1.8e To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF Technet To temporarily halt or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/archives Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 ----------------------------------------------------- --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 1.8e To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF Technet To temporarily halt or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/archives Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 -----------------------------------------------------